AQA Biology B2 - Unofficial Mark Scheme

↑↑↑ In the poll above, and answer like '> 30%' would mean between '30%' and '40%' ↑↑↑


Remember a question? Post your answers below.



AQA B2 Higher - Unofficial Mark Scheme (Updated Regularly) (Should have the last few questions of foundation)

1. Athlete Question
a)
i)
ii) The athlete was running for 1.5 minutes.
b) How do you know it was anaerobic respiration?
The athlete produced lactic acid

2. Pond weed Photosynthesis. - Move the light different distances from the pond weed. Count bubbles in one minute. Keep pond weed length the same.

3. Enzymes question. - Circle Question: Cytoplasm.

4. Plantains, Quadrats. To improve their investigation: Use random sampling, take more samples.
I got the number of plantains per square m at 3.125

5. Polydactyly Question

6. Removing bacteria from milk with catalase.
Advantages: Catalysts can be reused
Disadvantages: Enzymes can denature

7. Meiosis & Mitosis. The sperm cells were produces in the testes by Meiosis. The embryo divided by Mitosis.
For the question about the size of each cell:
6.6
13.2
6.6
3.3

8)
Foxes, Geographical isolation. Adapted differently. Mutation, So unable to breed. Different species.
Why were the foxes on the 3 islands varies but still the same species?
The islands have similar conditions so the two species adapted similarly and were so similar they could still interbreed so were still of the same species.


Note: The questions may not be in the right order.

This is a mix of my answers and those of the community but they are not guaranteed to be correct.

I put anus. Is it right?

no there were 10 quadrats, each one 25cm long. So 0.25 * 0.25 = 0.0625 and since there were 10 quadrats total area of all of them = 0.625 and there were 20 plantains. So 20/0.625 = 32 plaintains per m. Meaning in a field of 5000m then theres 160k, i remeber clearly im right now.

Did no one write that the athlete ran for 1 minute because wouldn't the blood rate remain high while he pays off oxygen debt?

Why was it Mitosis and not meiosis? It was producing sperm cells?

Producing sperm cells is Meiosis.

For the mean number of plantains. It is 2 not 3.6, The formula for the mean number is the total number of organisms divided by the number of quadrats. So 20/10 which is 2. So the total number of plantains in the field is 10,000

Nor me? Wasn't it the chance of getting polydactylly which I got 25%

1)Total number of plantains=202)Total area of 10 quadrats (in m^2)=6250
3)Mean number of plantains per m^2= 20/10=2
4)Total area of the field=5000
5)Estimated number of plantains in field=10,000

Okay thanks! I was just checking as someone had the advantages and disadvantages of enzymes as one question and then the advantages and disadvantages of hydrogen peroxide as another one?

So why was the answer Mitosis? I'm so confused, maybe I misread the question.

Why was it Mitosis and not meiosis? It was producing sperm cells?

Wasn't it 50%? Since the man is heterozygous (Dd) and the women in (dd)
Dd Dd dd dd

Posted from TSR Mobile

Producing sperm cells is Meiosis.

That's what i did aswell. I put 1.5 first then crossed it out...🙄